Electric key socket



May 10, 1927.

C. S. MALLETT ET AL ELECTRIC KEY SOCKET Filed May '7. 1925 Inventors. Charles S.MO lett,

wn hum J. Aldis, by @M):

Their Attorneg.

Patented May 10, 1927.

warren s'r CHARLES STANLEY MALLETT AND WILLIAM J; ALDIS, F TORONTQ, ONTARIU.

CANADA, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC KEY SOCKET.

Application filed May 7, 1925. Serial No. 28,654.

Our invention relates to improvements in electric key sockets of the type in which the sliding contact is operated by an inclined or Z-cam, and the object of the invention is to simplify the construction so that it comprises a minimum number of parts, consequently cheapening the cost of construc- 'tion and assembling, and at the same time to devise a socket in which means independent of the key is provided for controlling and limiting the movement of the slidingcontact to a definite length of. stroke so that the length of such stroke will not be affected by inaccuracies in the structure of the containing porcelain or looseness of the key staff in its support, in which the circuit is definitely broken at the centre contact only when the lamp is unscrewed, thereby eliminating accident through any possibility of the screw shell remaining alive, in which the key, sliding contact and terminal connection to the sliding contact are connected together to form a unitary structure insertible as a single unit into the porcelain, in which the shell is rigidly connected to the porcelain base positively to prevent any tendency to rotary movement between the shell and the base, in which the sliding contact and stationary contact are so constructed that both members of the sliding contact will always positively engage with the stationary contact, in which the stationary and sliding contacts are definitely positioned within the porcelain body, and in which the current passing through the sliding. contact is always definitely divided between the members of the contact, and it consists es-, sentially of the arran ement andconstruction'of parts hereinafter more particularly explained. Q 7

Fig. 1 is a perspective View of our key socket with outer shell removed; Fig. 2 is a similar view to Fig. 1 looking at the reverse side Fig. 3 is a perspective detail of one of the divided members of a porcelain base showing the centre contact in engagement therewith; Fig. 4 is a similar view to Fig. 3 showing the other member of the porcelain body with the stationary contact, sliding contact and key mechanism for opera ating the sliding contact in position; Fig. 5

is a similar view to Fig. 3 with the centre" contact removed and arranged for engagement with the parts shown in Fig. 4; F ig'.

6 is a similar view to Fig. 5 showing the porcelain body member opposing the body member shown in Fig. 5, the centre contact,

sliding contact and key mechanism removed therefrom; Fig. 7 is a perspective detail of the centre contact; Fig. 8 is a. sectional view through our key socket taken parallel to the key staff Fig. 9 is a similar view to Fig.

8 taken at right angles to the key staff;

Fig. 10 is a perspective detail of our screw shell, and Fig. 11 is a perspective view of the key mechanism.

In the drawings like characters of refer ence indicate corresponding parts in each figure. The divided base members 1 and 2 are provided, respectively, with opposing transverse recesses 3 and 4 forming a transverse orifice5, in which the key mechanism depressed portion 8 to permit'the free movement of the cam mechanism also hereinafter described.

Extending out from the bottom of the recess 3 is an inclined saw-cut or slit 9 for the reception of the stationary center centact hereinafter described. 10 is a shallow recess formed in the wall of therecess 3 and which serves as locating means for the sliding contact support, as will hereinafter appear. 11 is a rectangular projection extending radially from the bottom of the base member 1 and terminating at one end in a recess 12', see Fig. 1. 1 3 is an orifice extending through the member 1 centrally thereof and at rightangles to the recess 3 fora purpose which-will hereinafter appear.

.As above described, the body member 2 is provided with a recess4'opposing the recess 3. This member is also provided, with an inclined bearing face lewhich opposes the bearing face 6 of the member 1' and an inclined bearing face 15 opposin they bearing face 7., Below the recess 4 the member 2- is provided with a saw cut or slit opening 16 opposing the slit 0 ening 9 of the mem her 1, and with a shal 0w recess 17' in horizontal alignment with the recess 10. '18 is an orifice extending throu h the member 2 in diametrical alignment with the orifice 13.

Themember 2 is also provided with a projection 19 corresponding to the projection 11. 20 is a centre contact which is formed of a metal stri) the main portion 21 of which fits into the opposing slits 9 and 16. The upper end of the portion 21 is turned horizontally as indicated at 22, the extreme end being turned up at 23 to form a stop projection, for a urpose which will hereinafter appear. T is upper extremity of the portion 21 where it bends horizontally into the portion 22 is bent upward to forms transverse rib 23 with which the sliding contact hereinafter described contacts. The lower end of the centre contact 20 is reduced at 24 and turned horizontally as indicated at 25 beneath the projections 11 and 19. It will be seen that when the centre contact is inserted in the slit openings 16 and 9, and the members 1 and 2 of the body secured together, that such centre contact will be definitely held and located in position and it in turn serves as a dowel to retain the base members 1 and 2 in alignment.

\Ve will 'now describe the sliding contact and key mechanism by which it is operated. 26 is a line terminal contact in the form of a carrying frame comprising a base plate 27, an upturned flange 28 extending along one longitudinal edge of the base plate 27 and an upturned portion 29 forming a vertical wall extendin from the opposite edge of the base plate. lfihen in position, the base plate 27 rests upon the horizontal lower wall of the recesses 3 and 4, the flange 28 bearing against the side of the recess 4 and the wall 29 hearing against the side of the recess 3 so as to fit exactly within the orifice 5 when the base members 1 and 2 are in assembled position. The inner or right hand end of the base plate)? is provided with a down turned shoulder 30 which fits into the cross grooves or recesses 10 and 17, thereby delinitely positioning the frame 26 within the orifice 5 formed between the members 1 and 2. plate 27 is provided with an upturned por tion 31 opposite to the upturned portion 23 of the stationary contact. the upturned portion 23 forming a limiting stop for limiting the movement of the right hand stroke of the movable contact in one direction and the upturned portion 31 limiting the stroke of the movable contact in the opposite direction. I

The wall 29 is provided with an inturned horizontal portion 32, the inner end of which is formed into a bearing sleeve 33 lll'WlllCll the left hand end of the key stall" hereinafter described is journaled. 34 is a bracket extending from the wall 29 in the direction of the stationary contact, the extreme end of The outer or left hand end of the base eeann the tongue being provided with an inturned horizontal ortion 35 which is formed into a bearing s eeve 36supporting the key staff in proximity to its right hand end. 37 is a bracket bent outward from the oppositev '38-. the end of the screw extending into the notch or recess 4*, see Fig. 6. 39 is a key stafi and internicdiately between the bearings 33 and 36 it is formed into an inclined cam or 2 portion 40, while at the right hand end is a key handle 41. 42 is a sliding contact which is movably mounted upon the base plate 27 between the flange 28 and wall 29. The sliding contact 42 is bent up at one end, as indicated at 43 and turned horizontally to form a compound curve, as indicated at 44, the extreme end of the curved portion 44 extending upward and contacting with the inclined portion 40 of the inclined or Z cam, the contacting edge being slightly turned over, as indicated at s 45, to permit of free movement when in engagement with the cam.

The horizontal body of the sliding contact 4-2 is divided by a V notch into two members 46 and 47, see Fig. 11, resting normally or when the device is in the off position uponthe base plate 27. \Vhen the handle 41 is turned so that its pointer 41 is directed downward instead of u ward, thereby reversing the position of the inclined cam 40. the curved portion 44 of the sliding contact is compressed downward and therefore such sliding contact is carried in the direction of arrow at right of Fig. 11 by means of the expansive force of the curved portion 4+1 coacting with the inclined surface of the cam 40,and thereby carrying the contact members 46 and 47 into bearing contact with the upper face of the transverse rib 23, and completing the circuit from the centre contact to the sliding contact.

Itwill be seen when in this position that distributed contact of the members -16 and at? with the stationary contact is assured, and there is no danger of these contacts be coming out of align and detrimcntally affecting the contact.

48 is a screw shell for the reception of the lamp base. The screw shell 48 is provided in its base with an orifice 49 into which the rectangular base projection members 11 and 19 extend. 50 and 51 are lugs stamped upward from the end of the shell. each )rovided with an orifice 52, such lugs extending into the diametricall positioned base recesses 12, as indicate in Fi al). 53 is an assembly screw which extends through the orifices 52 of the lugs 50 and 51 and through ll l the orifices 13 and 18 of the base members 1 and 2, thereby securing the screw shell rigidly to the base members 1 and 2 and the latter in assembled relation. 54 is a plate extending into a vertical recess formed in the body member 2, the lower end of the plate being provided with a threaded orifice 56 into which the screw 53 extends and thereby forming a securing nut for such screw. The upper end of the plate 54 is provided with an internally threaded orifice 56 into which a terminal screw 57 is threaded.

In constructing our device it will be readily seen from the above description that the key, including the key staff 3%) and cam 40. together with the sliding contact -12, areheld assembled in the carrying frame 26 and thereby form a unitary structure in which the contact bracket 37 carrying the screw 38 is incorporated and which in assembling may be placed in the porcelain body of the socket as a single unit. Also by our construction the downturned shoulder 30 forms a locating means by which the mechanism is definitely located in position within the body in such a way that it cannot move. By providing the upturned stop portion 31 of the base plate 27 of the frame 26 and the upturned portion 23 of the centre contact 20, we provide limiting means for the movement of the sliding contact 42 at each end of a stroke which is absolutely independent of the construction of the porcelain body, and the length of the stroke of the sliding contact will therefore not be affected by any breakage or'faulty structure in such body. At the same time the length of stroke of the sliding contact will not be affected by any longitudinal movement of the key staff 39 within its bearings should such occur. It will also be noted that by our construction, when a lamp is unscrewed from the shell 48, a definite break is made between the centre contact 20 and the centre contact of the lamp.

It will also be noted that by our construction the shell 48 is rigidly secured to the base formed by the members 1 and 2 so that it cannot have any rotary movement by reason of the lugs 50 and 51 fitting within the recesses 12 and the securing screw 53 extending through such lugs and the porcelain body. Furthermore, the rectangular projection formed by the projection members 11 and 19 extending into the corresponding orifice 49 in the shell base also prevents any tendency to this movement of the shell. If desired, a cross groove, orifice or depression 59 may be formed between the slit opening 16 and the cross groove 17. By this means the flash between the stationary and movable contacts is deflected into such depression and prevents the oxidizing of the porcelain at this point.

It will be seen that we have devised a very simple construction of key socket in which the length of stroke of the sliding contact will not be affected by the inaccuracies in structure of the porcelain base or the looseness of the key staff in its hearings. in which the circuit is always broken at the centre contact, in which the key sliding contact and terminal connection through the sliding contact are incorporated in a unitary structure which may be inserted in the porcelainbody as a single unit, and in which the con-' nection between the porcelain base and-shell is of a rigid nature which will absolutely prevent any tendency of the shell to work loose on the base.

It will also be seen that by providing the transverse rib portion 23 in the stationary contact coacting with the divided portion of the sliding contact, that the current passing through such contacts will be distributed between the members of the sliding contact.

\Vhile we have. shown and described the best embodiment of the invention known to us we do not desire to be restricted thereto.

lVhat we claim as new and desire to secure by Letters Patent of the United States, 1s:

1. In a key socket, the combination with the porcelain body having a transverse orifice. of two stationary contacts mounted within the body to extend into opposite ends of the aforesaid orifice, a slidable contact located within the transverse orifice to bridge the stationary contacts, an operating key adapted to impart longitudinal movement to the said sliding contact alternately in opposite directions. and stop portions on said stationary contacts extending across the transverse orifice with which the sliding contactalternately engages to limit the length of its stroke in opposite directions.

'2. In a key socket. the combination with the porcelain body divided into two members and provided with opposing recesses forming a transverse orifice and having opposing slits formed in each member of the body extending between the transverse orifice and the lower end of the body, arcentre contact formed of a metallic strip, the centre portion of which extends into the said opposing slits and having its ends turned in opposite directions respectively against the lower end of the body and a wall of the transverse orifice, a sliding contact mounted within the transverse orifice of the base and coacting with the stationary contact and key operated means for imparting movement in reverse directions to the sliding contact.

3. In a key socket, the combination with the porcelain base having a transverse orifice, of a sliding contact'mounted within the transverse orifice and forked to form two contact members, key operated means for iniparting movement to the sliding contact alall;

ternately in reverse directions, a stationary centre contact strip mounted within the body having its ends turned in opposite directions respectively against the end of the base and a wall of the transverse orifice, and forming a cross rib extending transversely of the orifice with which the divided 1nemhers of the sliding contact engage.

4t. In a key socket, the combination with the porcelain base having a transverse orilice having a cross groove formed inthe wall of the orifice of a frame provided with a downturned portion at its inner end tit-' ting); the cross groove and an upturned portion in its opposite end forming a limiting stop for the sliding contact when moving in one direction, bearing supports forming part of the aforesaid frame, a key stall mounted in the bearing supports, a sliding contact mounted in the frame, means operated by the turning of the key statl' for imparting longitudinal movement in reverse directions to the sliding contact, a stationary centre contact strip extending from the end of the base and turned horizontally into the aforesaid orifice and having an upturned end forming a limiting stop for the sliding contact when moving in the opposite direction.

5. In a key socket, the combination with the porcelain base having diametrically opposite recesses in proximity to its lower end and a diainetric orifice extending through the body between the recesses, a screw shell provided with apertured lugs stamped eutward from the end thereot and extending into the dianietric recesses of the body, and a screw extending through the apertures ot the lugs and the orifice of the base :tor connecting the parts together.

6. In a lcey socket, the combination with the porcelain base having diametrically opposite recesses in proximity to its lower end and having: an orifice extending through the. body between the recesses and having a. vertical recess extending from one of the aforesaid recesses towards the upper end of the base. of a screw shell provided with apertured lugs extending upwardly into the diainetric recesses, a screw extending through the aligned orifices and a plate having a threaded orifice at one end into which the aforesaid screw is secured and having a threaded orifice at the opposite end and a terminal screw secured in the last mentioned orifice.

In witness whereof, we have hereunto set our hands this 21st day of April, 1925.

CHARLES STANLEY MALLETT. WllliLLtlll J. ALDIS. 

